The prevalence and significance of microalbuminuria is not well elucidated in patients with essential hypertension. In newly detected hypertension, its prevalence ranges between 23 and 37% and albuminuria is usually well correlated with the level of arterial pressure. Interestingly, albuminuria is enhanced in overweight hypertensive patients. Antihypertensive treatment has variable influence on albuminuria, and converting enzyme inhibitors, in contrast to other agents, tend to partially correct this abnormality. Whether microalbuminuria represents a predictor of the future development of nephrosclerosis and ultimately renal failure, or a predictor of cardiovascular morbidity deserves to be investigated.